Whenever Fire Lord Ozai attacks, you may sacrifice another creature. If you do, add an amount of equal to the sacrificed creature's power. Until end of combat, you don't lose this mana as steps end.

: Exile the top card of each opponent's library. Until end of turn, you may play one of those cards without paying its mana cost.

Whenever you cast a spell during an opponent's turn, you get an experience counter.

Whenever Katara attacks, you may draw a card for each experience counter you have. If you do, discard a card.

When Aang enters, airbend another target creature. (Exile it. While it's exiled, its owner may cast it for rather than its mana cost.)

Whenever one or more creatures you control leave the battlefield without dying, you get an experience counter.

At the beginning of your upkeep, create a 1/1 white Ally creature token for each experience counter you have.